I mean some of these reviews may not be genuine. I went over a few users who've made a review on Rollbit and most of them only have 1 or 2 reviews and some got more than a couple but are all negative reviews against another crypto casinos.
The most recent one it's kind of ridiculous. Just because a casino do not require KYC means it's suspicious for being a scammer. I guess he's not aware that most crypto casino licenses are a Curacao license, it may not be as strict as the other traditional casino license provider but it works for crypto casinos.
In fact, Rollbit just had their license annual reviewed last month.
They also got more positive reviews from different review platforms anyway. 4.3 rating in Trustpilot is not even bad, considering the competition in this field these days. Competitors may possibly make unnecessary actions to put the other competitors down.